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Date:      Thu, 29 Nov 2018 06:36:46 -0500
From:      Ken M <>
Subject:   Power management
Message-ID:  <20181129113646.GA45451@ultron>

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Recently returning as a freebsd desktop/laptop user. I have a thinkpad t440 that
previously ran openbsd and now has freebsd 11.2 on it.

I am noticing that it seems freebsd is consuming the battery slightly faster.
Granted that could easily be explained by perhaps usage.

However one thing I cannot seem to dig up is setting a defauly boot brightness.
Now the t440 brightness keys work just fine. In fact no tweaks needed. So I am
guessing it is a bios function. I was thinking a sysctl setting would do it but
case in point.

sysctl hw.acpi
hw.acpi.acline: 0
hw.acpi.battery.info_expire: 5
hw.acpi.battery.units: 2
hw.acpi.battery.state: 1
hw.acpi.battery.time: 267 96
hw.acpi.thermal.tz0._TSP: -1
hw.acpi.thermal.tz0._TC2: -1
hw.acpi.thermal.tz0._TC1: -1
hw.acpi.thermal.tz0._ACx: -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
hw.acpi.thermal.tz0._CRT: -1
hw.acpi.thermal.tz0._HOT: -1
hw.acpi.thermal.tz0._PSV: -1
hw.acpi.thermal.tz0.thermal_flags: 0
hw.acpi.thermal.tz0.passive_cooling: 0 -1
hw.acpi.thermal.tz0.temperature: 36.1C
hw.acpi.thermal.user_override: 0
hw.acpi.thermal.polling_rate: 10
hw.acpi.thermal.min_runtime: 0
hw.acpi.cpu.cx_lowest: C8
hw.acpi.reset_video: 0
hw.acpi.handle_reboot: 1
hw.acpi.disable_on_reboot: 0
hw.acpi.verbose: 0
hw.acpi.s4bios: 0
hw.acpi.sleep_delay: 1
hw.acpi.suspend_state: S3
hw.acpi.standby_state: NONE
hw.acpi.lid_switch_state: S3
hw.acpi.sleep_button_state: S3
hw.acpi.power_button_state: S5
hw.acpi.supported_sleep_state: S3 S4 S5

No brightness settings there. On a whim I thought I would see what xbacklight
could do for me.

xbacklight -get
No outputs have backlight property

So I guess the long and short of my question is what would be the correct way to
set the brightness at boot? And also is there perhaps any other tweaks I could
make to improve battery life?

Thank you,

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